Merge branches 'regset.x86', 'regset.ia64', 'regset.sparc' and 'regset.arm64' into work.regset

Author: Al Viro

arch/arm64/kernel/ptrace.c

@@ -1237,6 +1237,22 @@ enum compat_regset {
 	REGSET_COMPAT_VFP,
 };
 
+static inline compat_ulong_t compat_get_user_reg(struct task_struct *task, int idx)
+{
+	struct pt_regs *regs = task_pt_regs(task);
+
+	switch (idx) {
+	case 15:
+		return regs->pc;
+	case 16:
+		return pstate_to_compat_psr(regs->pstate);
+	case 17:
+		return regs->orig_x0;
+	default:
+		return regs->regs[idx];
+	}
+}
+
 static int compat_gpr_get(struct task_struct *target,
 			  const struct user_regset *regset,
 			  unsigned int pos, unsigned int count,
@@ -1255,23 +1271,7 @@ static int compat_gpr_get(struct task_struct *target,
 		return -EIO;
 
 	for (i = 0; i < num_regs; ++i) {
-		unsigned int idx = start + i;
-		compat_ulong_t reg;
-
-		switch (idx) {
-		case 15:
-			reg = task_pt_regs(target)->pc;
-			break;
-		case 16:
-			reg = task_pt_regs(target)->pstate;
-			reg = pstate_to_compat_psr(reg);
-			break;
-		case 17:
-			reg = task_pt_regs(target)->orig_x0;
-			break;
-		default:
-			reg = task_pt_regs(target)->regs[idx];
-		}
+		compat_ulong_t reg = compat_get_user_reg(target, start + i);
 
 		if (kbuf) {
 			memcpy(kbuf, &reg, sizeof(reg));
@@ -1541,9 +1541,7 @@ static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
 	else if (off == COMPAT_PT_TEXT_END_ADDR)
 		tmp = tsk->mm->end_code;
 	else if (off < sizeof(compat_elf_gregset_t))
-		return copy_regset_to_user(tsk, &user_aarch32_view,
-					   REGSET_COMPAT_GPR, off,
-					   sizeof(compat_ulong_t), ret);
+		tmp = compat_get_user_reg(tsk, off >> 2);
 	else if (off >= COMPAT_USER_SZ)
 		return -EIO;
 	else
@@ -1555,23 +1553,34 @@ static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
 				    compat_ulong_t val)
 {
-	int ret;
-	mm_segment_t old_fs = get_fs();
+	struct pt_regs newregs = *task_pt_regs(tsk);
+	unsigned int idx = off / 4;
 
 	if (off & 3 || off >= COMPAT_USER_SZ)
 		return -EIO;
 
 	if (off >= sizeof(compat_elf_gregset_t))
 		return 0;
 
-	set_fs(KERNEL_DS);
-	ret = copy_regset_from_user(tsk, &user_aarch32_view,
-				    REGSET_COMPAT_GPR, off,
-				    sizeof(compat_ulong_t),
-				    &val);
-	set_fs(old_fs);
+	switch (idx) {
+	case 15:
+		newregs.pc = val;
+		break;
+	case 16:
+		newregs.pstate = compat_psr_to_pstate(val);
+		break;
+	case 17:
+		newregs.orig_x0 = val;
+		break;
+	default:
+		newregs.regs[idx] = val;
+	}
+
+	if (!valid_user_regs(&newregs.user_regs, tsk))
+		return -EINVAL;
 
-	return ret;
+	*task_pt_regs(tsk) = newregs;
+	return 0;
 }
 
 #ifdef CONFIG_HAVE_HW_BREAKPOINT